TORONTO -- A drunk driver who went on a personal demolition derby has been sent back to prison for another nine months after Ontario's top court increased his sentence.

In a ruling released Wednesday, the court said the original punishment handed David Clouthier -- two intermittent sentences totalling five months -- was demonstrably unfit given that he caused three crashes in the space of 15 minutes -- and fled each time.

"These were serious offences that demonstrated a complete disregard for the lives and safety of others lawfully using the streets of an urban area on a summer evening," the Court of Appeal said. "Repeated flights from the scenes of the accidents displayed a callous indifference to fellow motorists."

Court records show Clouthier, 21, got into his truck one evening in June 2013 after consuming several drinks. He soon rear-ended another vehicle at an intersection, reversed, drove over a median, and fled into a residential area.

A few minutes later, he rear-ended a second vehicle. Again, he fled at speeds of up to 130 kilometres an hour, before slamming head-on into another vehicle, causing serious injuries to one passenger. This time, Clouthier climbed out the window of his badly damaged truck and tried to run away but witnesses were able to grab and hold him for police.

At trial, the first-time offender pleaded guilty to impaired and dangerous driving causing bodily harm, and to failing to stop at the scene of an accident.

Despite "numerous aggravating factors," Ontario court Judge Ann Alder sentenced him in Ottawa last year to a total of five months in custody. Alder also decided to give him the option to serve his time in two instalments -- which he accepted -- because he had recently found full-time work.

The Crown appealed, saying the punishment was illegal because it got around rules for maximum intermittent sentences, and unfit given the crime.

The Court of Appeal agreed the sentence circumvented the rules. The court also found that although Clouthier was remorseful and had taken strides to clean up his act, the five-month punishment wasn't enough.

"Without any regard for the health or safety of the occupants of any of the vehicles he struck, he fled each scene, accelerating away in one instance to speeds at least twice the posted limit in residential areas," the court said.

"The sentence imposed, essentially five months, fails to reflect in any meaningful way the predominant sentencing objectives of general deterrence, denunciation, and protection of the public."

The Appeal Court decided a total term of 15 months would be appropriate and, given time already served and other pre-sentence credit, sent Clouthier back to serve another nine months. The court gave him 72 hours to surrender into custody.